Outlook PST Was Not Cleanly Closed by the Last Program – Solved

Published By Jamie Kaler

Approved By Rollins Duke

Published On October 8th, 2025

Reading Time 6 Min Read

If you are seeing the Outlook PST was not a cleanly closed error then it can happen due to improper closing, becoming corrupted, or shutting down unexpectedly. In this guide, we will explain common causes, show you how to detect symptoms, walk you through the Microsoft inbuilt Outlook Inbox Repair Tool and Expert preferred choice and also share prevention tips to avoid this issue in the future.

What Causes the “Outlook PST Was Not Cleanly Closed” Error?

If you close your Outlook or system unexpectedly then the PST file may not save recent changes and shows Outlook PST was not cleanly closed by the last program.
Forcing Outlook closure or experiencing a crash can leave the PST file incomplete.
Suspicious Add-ins or other software can block Outlook to close PST files correctly.
Highly damaged hard drives can prevent PST file corruption issues.
Malware or corrupted Outlook data can interfere with Outlook, causing the PST file not to be cleanly closed.
If the PST file is on a network or external drive that disconnects, Outlook will take lots of time to load it.

Recognizing Symptoms & How This Error Manifests

Outlook may show an error message PST file was not cleanly closed or cannot be opened.
PST files may take a long time to open or fail to load.
You might notice missing emails, folders or recent changes when you are accessing your Outlook profile.

First Steps to Try Before Deeper Repair

Always backup Outlook data before applying any approach.
Close Outlook and PC in a proper manager to ensure the PST file closes cleanly.
Turn-off suspicious Add-ins or check Outlook Safe Mode to prevent add-ins interferences to opening the PST file.

Method 1. Run ScanPST(Outlook Inbox Repair Tool)

Close Outlook completely.
Locate ScanPST on your pc Usually in C:\Program Files\Microsoft Office\root\Officexx\.
Double-click on ScanPST. Exe to open it.
Click on Browse to choose PST file.
Press Repair to turn into healthy Outlook files.

Method 2. Repair PST Using Microsoft Support Steps

Open the Control Panel and click on Mail then hit the Data files.
Select the PST file and tap on Settings and press on Compact Now.
If the issue persists, Microsoft recommends creating a New Outlook profile.

Method 3. Create a New Outlook Profile

Navigate to the Control Panel and hit Mail.
Tap on Show Profiles and press on Add.
Give the New Profile name.
Follow the wizard to add your email account.
Select Prompt for a profile to be used.
Open Outlook with a new profile and import your repaired PST.
Hit on file and tap on Open and export and hit on Import/Export.

How to Fix Outlook PST Was Not Cleanly Closed via Automated Method?

If you have tried all manual methods and PST file issue not resolved. Then, we recommend you to choose RecoveryTools PST Repair Tool as this software can make healthy Outlook files. To use this utility you just need to click on download button and enjoy its hassle-free working steps as we have shared below:

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Steps to Fix Outlook Was Not Cleanly Closed

Download and launch Recommended Software on your pc.
Click on Select files or folder to choose Outlook files to import.
Choose the mailbox folder and uncheck all unwanted folders.
Select the PST file in the list of Saving options and choose the destination path.
Press on Repair to get healthy Outlook files.

Benefits to opt Recommended Software

You can also use Outlook data as backup as it also supports various popular saving formats for converting PST to PDF, MBOX, EML, MSG and many more.
It is reliable in both cases to recover single or batch Outlook files at one shot.
With this wizard, any user can easily operate this tool without requiring any advanced technical knowledge.
This software also offers split PST file, separate PST per user, and ignores system folder hierarchy as you need.
This tool offers you to import PST to Office 365, Thunderbird, Zimbra, and many more for maintained results.
It is also reliable to recover deleted items from the PST file and can restore any level of damaged Outlook PST file.

Preventive Measures & Best Practices

Always archive, split or compact PST file to maintain size and stay away from file corruption issues.
Run Regular Antivirus Scan to protect Outlook files from viruses, malware or unwanted interference.
For oversize or highly damaged PST files, use specialized tools to restore Outlook data safely.
Check permissions of the PST file as no other program interferes with accessibility of the PST file.
If all fails, contact Microsoft Support for expert guidance to recover your Outlook data.

Common Queries

How to Repair a PST File that Wasn’t Closed Properly?

Close Outlook and backup PST file first. Then, use Microsoft Outlook Inbox Repair Tool to detect and fix errors. If a file is heavily damaged, then you can create a New Outlook profile or use Expert PST Recovery to make healthy files.

Why does Outlook Not Close Properly?

Outlook may not close properly or it may crash, improper shutdowns, due to large PST files, network interruptions or interference from antivirus/backup software. These issues can leave PST files open and cause errors on the next launch.

How do I Repair a PST file Without ScanPST?

If Outlook Inbox Repair Tool fails to fix, use an expert recommended tool to make a healthy Outlook file or you can also create a New Outlook profile and import the PST file, restore a backup copy to fix PST file corruption.

Conclusion

In this tutorial, we have explained the best techniques to fix Outlook PST Was Not Cleanly Closed by both Outlook inbuilt and expert tried and tested methods. The manual approach is reliable only for minor corruption. So, we recommend you to choose the Expert Recommended Method to make healthy Outlook files without facing any limitations.